Applications in the medical field requiring aseptic connecting interfaces include bioprocessing, nutrition support, drug delivery, and vascular access procedures among many others. These applications often require coupling at least two fluid connectors in a non-sterile setting in order to transfer a sterile fluid from one sterile site to another.
One common device used in infusion therapy markets are needle-free devices, which may be attached to a variety of ports, vials, or other connectors such as those located at the proximal end of an indwelling vascular catheter.
FIGS. 1A-1D show various types of needle-free devices according to the related art. In particular, FIGS. 1A-1D illustrate the mechanism by which two types of needle-free systems function, demonstrating the attachment of a male needleless connector to the female connector on the proximal end of a needleless adapter, and a re-sealable elastomeric septum disposed within the needleless adapter. The needleless adapter illustrated in FIG. 1A is often called a luer access device (LAD), since it allows an attaching medical article with a male luer tip to create a fluid-tight connection with a distal fluid system. The series FIGS. 1A-1B shows a male luer tip 105 used to depress a re-sealable split septum 110 within the female connector to provide fluid communication. FIGS. 1C and 1D show the male connector as a blunt-tip cannula 115 used to access a re-sealable split septum 120 disposed within the female connector at the proximal end of the needleless device.
FIGS. 2A-2D show various types of needleless fluid systems of the related art. In particular, FIG. 2A shows a needle-free device with a single septum that is displaced upon attachment of the male connector. The device contains no internal features apart from the re-sealable septum. FIG. 2B shows a type of needle-free device that includes an internal actuator to achieve positive fluid displacement upon detachment of the male connector. The positive fluid displacement causes the fluid to flow between the outer housing and the internal actuator component and results in a small release of fluid through the distal tip. FIGS. 2C and 2D show a device containing an internal blunt-tip cannula which pierces a split septum as the elastomeric septum is displaced within the device upon attachment of the male connector. Fluid flows through the blunt tip cannula within the device and through the distal tip. This design results in a neutral fluid displacement as the withdrawal of the male connector causes the septum to re-seat around the internal cannula with minimal fluid displacement (usually less than ±10 microliters).
In non-sterile environments, microbial contamination between fluid fittings such as those used in needle-free systems occurs when the interface between the male and female tips is not adequately disinfected prior to attaching the connecting article. When used in patient care settings, contamination may result in an increased risk of infection as organisms may be spread to other surfaces along the distal fluid lumen as well as to the patient.
Needleless systems that do not isolate the infusion fluid from poorly disinfected external surfaces, such as those in FIGS. 3A and 3B, are more susceptible to device contamination since the sterile fluid contained within the attaching article may potentially contact a surface pathogen 305. Likewise, devices whose external surface(s) touch internal features of the fluid flow channel 310, such as those in FIGS. 3C-3E, are also susceptible to a higher risk of device contamination since microbial transfer can occur between these surfaces in the event of inadequate disinfection. In this latter case, future disinfection procedures that address only external surfaces of the device will be insufficient in preparing the device for access since internal features cannot be disinfected.
As shown by the discussion of the related art above, currently available needle-free systems have design features that can lead to microbial transfer between external sources and aseptic fluid systems. Accordingly, it would be advantageous to provide a needle-free system that is capable of providing an aseptic connection by preventing exposed surfaces on the female connector from contaminating both the attaching male connector and internal surfaces which are part of the fluid flow pathway.